From ef94f77f8c827a2395f1c40f53311a3b1f20bc5b Mon Sep 17 00:00:00 2001
From: Daniel Monroe <39802758+Ergodice@users.noreply.github.com>
Date: Fri, 23 Jun 2023 18:36:27 -0400
Subject: [PATCH] Update default net to nn-a3d1bfca1672.nnue

faster permutation of master net weights

Activation data taken from https://drive.google.com/drive/folders/1Ec9YuuRx4N03GPnVPoQOW70eucOKngQe?usp=sharing
Permutation found using https://github.com/Ergodice/nnue-pytorch/blob/836387a0e5e690431d404158c46648710f13904d/ftperm.py
See also https://github.com/glinscott/nnue-pytorch/pull/254

The algorithm greedily selects 2- and 3-cycles that can be permuted to increase the number of runs of zeroes. The percent of zero runs from the master net increased from 68.46 to 70.11 from 2-cycles and only increased to 70.32 when considering 3-cycles. Interestingly, allowing both halves of L1 to intermix when creating zero runs can give another 0.5% zero-run density increase with this method.

Measured speedup:

```
CPU: 16 x AMD Ryzen 9 3950X 16-Core Processor
Result of 50 runs

base (./stockfish.master ) = 1561556 +/- 5439
test (./stockfish.patch ) = 1575788 +/- 5427
diff = +14231 +/- 2636

speedup = +0.0091
P(speedup > 0) = 1.0000
```

closes https://github.com/official-stockfish/Stockfish/pull/4640

No functional change
---
 AUTHORS        | 1 +
 src/evaluate.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/AUTHORS b/AUTHORS
index ff224954..2e9ae780 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -48,6 +48,7 @@ clefrks
 Dale Weiler (graphitemaster)
 Daniel Axtens (daxtens)
 Daniel Dugovic (ddugovic)
+Daniel Monroe (Ergodice)
 Dan Schmidt (dfannius)
 Dariusz Orzechowski (dorzechowski)
 David (dav1312)
diff --git a/src/evaluate.h b/src/evaluate.h
index b9d7231d..c3321965 100644
--- a/src/evaluate.h
+++ b/src/evaluate.h
@@ -39,7 +39,7 @@ namespace Eval {
   // The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
   // for the build process (profile-build and fishtest) to work. Do not change the
   // name of the macro, as it is used in the Makefile.
-  #define EvalFileDefaultName   "nn-5af11540bbfe.nnue"
+  #define EvalFileDefaultName   "nn-a3d1bfca1672.nnue"
 
   namespace NNUE {
 
-- 
2.39.2